Damage to bee colonies resulting from epidemic diseases caused by mites has become a serious threat to bee stocks throughout the world. Aside from leading to decreases in honey production, the spread of these mites also pose a threat to any form of agriculture which relies on honey bee pollination.
U.S. Pat. No. 4,867,731 teaches a method for the detection of infestation of bees with mites comprising placing a replaceable insert with an upwardly facing adhesive trapping surface with a spaced screen mounted thereover into a hive, wherein the spaces in the screen are large enough for mites to pass through (and onto the adhesive surface) but too small for the bees to pass through. The inventors note that this method can also be used in combination with treatments for evaluating the effectiveness of various miticides or in combination with irritants, such as Fluvalinate strips or tobacco or dry grass smoke.
However, when treating honey bees with fluvalinate strips, up to 60 percent of the varroa mites, which fall onto the observation material placed below the colony, are alive. It has been observed that these still-viable mites can survive without food for up to 7 days. During this time period, mites which fall from the bees are able to re-attach themselves to honey bees and re-infect the hive. Because not all of the mites are killed quickly when fluvalinate strips are used, but continue to remain viable for up to 7 days, 20-30% of these mites become re-introduced into the honey bee colony, and may hasten the development of fluvalinate resistance. Furthermore, fluvalinate is known to irreversibly contaminate all hive products including wax and honey. It has also been demonstrated that low residual levels of pesticides can contribute to mite resistance.
U.S. Pat. No. 4,876,265 teaches a process for controlling mites on honey bees using 2-(2,4-dimethyl-phenylimino)-3-methylthiazoline or derivatives thereof as the active ingredient. The composition is applied to fumigant strips or prepared as a concentrate. In use, the compositions are either fed to the bees or arranged to drip onto the bees.
U.S. Pat. No. 5,069,651 teaches a method and device for removing parasites from bees which comprises forcing heated air into a hive such that the temperature within the hive is elevated to a temperature that is not tolerated by the mites but is tolerated by the bees. Specifically, the air within the hive is heated to 120-130xc2x0 F. for approximately 15 minutes. In some embodiments, vegetable oil is sprayed into the flow of heated air. The device is fitted on top of the bee hive and includes a thermostat for monitoring air temperature.
U.S. Pat. No. 5,162,014 teaches a method for treating honey bees infected with mites comprising exposing the hive to a magnetic field which is greater than two orders of magnitude stronger than the magnetic field of the earth.
Formic acid has previously been used in liquid form to control mites in honey bees (apis mellifera). Formic acid is known as a desiccating material, and has been widely used, by various methods, to control mites within honey bee colonies. Scientific analysis confirms that a minute amount of formic acid will occur in pure honey. Apis cerana is another strain of bee and the natural host for varroa mites. Varroa has always been exposed to low levels of formic acid in the honey of apis cerana making it unlikely that these mites will become resistant to this material in the future. In one instance, a cardboard-like material soaked with formic acid and arranged to be inserted into a hive was developed. Others have used cheesecloth soaked with formic acid, containers with wicks, and formic acid in a gel. For example, U.S. Pat. No. 6,037,374 teaches gel compositions of formic acid and a gelling agent. The gel is used in various types of dispensers which allow emission of formic acid vapor. Alternatively, they note that the gel may be applied directly, for example, with a caulking gun. However, it is of note that while formic acid vapor is emitted during the warmer parts of the day, but levels of formic acid vapor dropped during cooler evening hours using the gel compositions, meaning that the formic acid vapor is not continuously applied in this method.
As will be appreciated by one knowledgeable in the art, application of varying levels of formic acid vapors over a long period of time may be less effective at killing the mites while being detrimental to the honey bees"" health. Clearly, an improved method for treating honey bees infected with mites is needed.
According to a first aspect of the invention, there is provided a method of treating honey bee diseases comprising:
providing a substantially air-tight reservoir containing a volatile material, said reservoir having at least one opening therein;
placing the reservoir in contact with a bee hive; and
heating the volatile material in the reservoir such that a vapor is produced from the volatile material, said vapor exiting the reservoir and entering the bee hive via said opening, said vapor having miticidal properties.
The opening may be metered for controlling the amount of vapor entering the hive.
The volatile material may be formic acid.
The reservoir may include a heater for heating the volatile material.
The heater may include a control unit for regulating the heater.
The reservoir may be placed in a bee hive.
According to a second aspect of the invention, there is provided a device comprising:
a reservoir for storing a quantity of a volatile material;
a heater for heating the volatile material; and
a control unit for regulating the heater.
The reservoir may be substantially air-tight and the reservoir includes at least one opening.
The opening may be metered.
The volatile material may be formic acid.
One embodiment of the invention will now be described in conjunction with the accompanying drawings in which: